Rockola 445 Read Out Issues

[mberry]

Hello All,

Backstory:

Got this rockola 445 off of FB Marketplace here in STL Missouri off a private owner.  Only info I had was 'not working.'  Got the unit home started checking fuses and they are all good aside from the mech one, which was blown.  After this I tested manually moving the gripper motor to see if the unit would engage the gripper arm, it was seized.  As a result I disassembled that unit, cleaned it of all the old grease and re-assembled.  

I turned on the unit at this point after installing a new appropriate fuse for the mech unit, and the arm returned back to place as it should.  Then a horrible grinding/knocking noise to find that the cam shaft on the back of the machine was off of its orientation.  I corrected this and tried the machine again.  

So now, is where I am stuck.  I turn on the unit, select a record and the write in completes and stops at the appropriate place.  Then the read out cycles and does not stop completing revolutions.

What I have tried so far to fix this:

Cleaned fully the contact rings and contact blades that ride on them per the article here:

jukeboxaddicts.proboards.com/thread/704/common-problems-400-series-phonos

I have not tested the hammer coils yet, I was able to get the selector assembly removed when cleaning and did notice coils on either side of the arm, but noticed they are fully covered in tape (likely factory).  Am I to cut the tape off of these to get access to the leads to test for ohms?

I also removed both write in and stop relays and cleaned them.

My other guess is maybe the wobble plate solenoid and/or the accumlator reset coil needs to be tested also with a multimeter?

Any advice/ guidance is appreciated.

[Ron Rich]

Hi MBerry,
Hammer coils are wired to the common, and one other of the long bladed contacts that ride the rings-- Wobble plate coil has already done it's job, if mech scans for a "pulled pin" ! Ron Rich

[mberry]

Ron, thank you so much for your reply and all the help you have given on this forum! I see the two red wires soldered together to where I think you are referring to as the "common." Also the black wires soldered to separate contacts. Am I right in thinking I would need to desolder the red wires to test the coils separately? I am getting a readout of 56.3 using a sperry dm-6250 multimeter set to ohms when I test them thus far.  

My apologies for what seem to me like questions from a noob, but i am in terms of testing electronics.

I again thank you for your time and assistance.

[Ron Rich]

Hi MBerry,
I can not re-call the color scheme - wires should come from the individual coils-- and if joined together on more then one post, must be separated to test individual coils-- Best I can do-- Ron Rich

[mberry]

Hey Ron,

I was able to test the first coil and get a reading of 53.3 when using the auto-range multimeter set to ohms. Does that seem correct to you?

[Ron Rich]

MBerry,
I dono-- can't remember what they should read-- ? All of the coils on both carriages are the same, and should read the same-- I don't trust "auto ranging" to read any "in circuit" devise. Ron Rich

[mberry]

Ron,

Agreed on the autorange multimeter, I'm going to research getting a proper one right away, it's time. Also I'll ask around on the reading of the coils, if I find anything I'll report back.

thank you!

[mberry]

This got solved.

It turns out the machine could only play B sides. Each time I tried A sides (which was all I was testing in the beginning), the read out would spin continuously. After some research into the schematics I found the issue was with the 'alternating dog.' After removing the 'gripper reversal bracket' and cleaning the 'dog' which would not rotate, both sides worked. I also cleaned the grooves really well that the dog rides in to ensure it would not get gummed up again.

This is related to this post:

jukeboxaddicts.proboards.com/thread/2878/rockola-playing-numbered-records-play